The invention relates to a two piece paperboard package for containing unit dose materials, the unit doses being encapsulated on an internal slide card within an outer sleeve. The package includes features that render it suitable for packaging such unit doses while meeting regulatory criteria for child resistance by the inclusion of a pull-out mechanism comprised of offset notches for withdrawing the internal slide card from the outer sleeve, in combination with a false bottom that provides additional support to the outer sleeve, and tear resistant lamination of at least a portion of the sleeve.
Unit dose packaging is an attractive packaging format for certain pharmaceutical applications because it is convenient, yet sturdy enough to be opened and closed numerous times until the course of medication is completed, and also enables the user to track the consumption of doses according to the prescribed schedule. Examples of such packaging are described in U.S. Pat. No. 6,047,829 (Johnstone), which is commonly assigned with the invention described herein. The Johnstone patent relates to a unit dose paperboard package that includes an outer paperboard sleeve, an inner paperboard slide card that is lockably retained within the sleeve. The sleeve includes a plurality of side panels operatively connected to each other such that one of said plurality of side panels includes a first inner slide card releasing means, and another of said side panels includes a second inner slide card releasing means, such that the inner slide card retaining and releasing means are located substantially adjacent to said unit dose dispensing means.
The invention described herein is an improvement over that described and claimed in U.S. Pat. No. 6,047,829, in that the package is rendered less susceptible to unintentional opening and has improved structural stability. Child resistance is a feature particularly desired for pharmaceutical packaging, and is mandated by the Poison Prevention Packaging Act of 1970. For a desired child resistance (CR) rating of F=1, a random sampling of the subject packages may not be compromised by an age specific test pool of children at a failure rate of greater than 10%. This general guideline is designed to ensure that the package has sufficient integrity against tampering by children. In view of this desired requirement, it is an object of the invention to provide a unit dose packaging system with improved child resistance, which prevents unauthorized access to the package contents.
In addition to child resistance, however, it is also desirable that the unit dose packaging system be senior friendly to permit easy withdrawal of the package contents with minimum manipulation. Such a withdrawal means should be easy to use even if the patient""s manual dexterity or strength is reduced. Accordingly, another object of the present invention is to provide a senior friendly package that can be easily manipulated by the user.
These objectives are met by the packaging system, articles and methods of the present invention, which are described and claimed below.
The invention meets the needs for child resistance and senior friendliness by providing a unit dose paperboard package having a locking feature that permits the package to be opened and closed during repeat usage, then disposed of when all the unit doses have been consumed. The package comprises an outer sleeve, which may be at least partially laminated to provide tear resistance, said sleeve further comprising an internal structural support formed from a panel extension thereof; and an internal slide card.
In one aspect, therefore, the invention comprises:
a) an outer sleeve including a plurality of side panels, a plurality of hinge panels, said side panels and hinge panels being operatively connected to each other; and wherein at least one side panel includes a foldable extension thereof, said extension being folded toward the interior of the sleeve to form a false bottom; and further wherein one of the side panels includes an internal slide card retaining element and a first inner slide card releasing element, and another of said plurality of side panels includes a second inner slide card releasing element; wherein the outer sleeve includes a pair of offset notches for grasping and removing an internal slide card; and wherein the outer sleeve is at least partially laminated with a polymeric film material; and
b) an internal slide card having encapsulated therein one or more blisters each containing a unit dose of a material to be dispensed, the slide card being comprised of a slide card body and an extension, the extension being folded inwardly over and being positioned parallel to the slide card body when the package is closed.
In another aspect, the invention comprises a blank for forming a lockable outer sleeve for housing an internal slide card of a unit dose package comprising a plurality of side panels and a plurality of hinge panels; at least one of said side panels comprising an extension thereof forming an internal slide card retaining element, and at least one side panel thereof additionally comprising a first internal slide card releasing element; and at least another side panel comprising a second internal slide card releasing element; and further comprising, in combination, a pair of notches, each notch being formed along an outer edge of the sleeve in an offset parallel relationship to the other, and a false bottom formed by a foldable extension of at least one side panel.
In yet another aspect of the invention, there is disclosed a method of packaging unit doses of a periodically dispensable material comprising:
a) cutting a blank for forming an outer sleeve from a substrate material;
b) forming an internal slide card from a substrate material, said internal slide card including a body and a foldable extension thereof;
c) folding the blank to form an outer sleeve including a plurality of side panels, the side panels having included therein at least one slide retaining means and at least one slide releasing means, at least one side panel comprising a foldable extension thereof which, when folded, forms a false bottom within the interior of the sleeve; the blank further including a pair of notches positioned in an offset parallel relationship to each other when the blank is folded;
d) encapsulating unit doses of a material onto the internal slide card;
e) folding the extension of the slide card to position the extension parallel to the body of the slide card;
f) inserting the folded slide card into the sleeve such that the extension thereof becomes slidably and lockably engaged with the slide retaining means in the side panels of the sleeve.
A unit dose package according to the invention is thus composed of an internal slide card and an outer sleeve. The outer sleeve or the internal slide card may be cut from any suitable material, for example plastic, paperboard or, if desired a laminate of paperboard and another foldable material, for example a foil or a polymeric film. Suitable paperboard materials are described, for example, in U.S. Pat. No. 6,047,829, the entire disclosure of which is herein incorporated by reference. The selection of this substrate may be made according to the packaging need, and accordingly, a substrate material generally recognized as safe (GRAS) by the FDA is also within the scope of the invention. In certain preferred embodiments, the substrate may be selected from a sheet of bleached sulfate board, solid unbleached sulfate board (SUS), clay-coated newsback (CCNB), or any other suitable board substrate, such a substrate preferably ranging in thickness from about 0.008 inches up to about 0.050 inches. For example, the paperboard may be clay coated on one side (C1S) or on both sides (C2S), with a coating such as a fluidized blend of mineral pigments selected from coating clay, calcium carbonate and/or titanium dioxide with starch or adhesive, or various combinations of these materials. Successive densification and polishing (via calendering) finishes each coated surface to a to high degree of smoothness and renders it suitable for graphics printing of superior quality.
The sleeve includes a plurality of side panels forming the wider surfaces of the package, these side panels being operatively connected by a plurality of hinge panels. Preferably at least one of the plurality of side panels includes an internal slide card retaining element and a first internal slide card releasing element, while another of the plurality of side panels includes a second internal slide card releasing element. In certain preferred embodiments, the internal slide card retaining elements are extension panels. The first internal slide card releasing element is preferably composed of a cut away region that includes a node for engaging an extension of the slide card in at least one side panel, while the second internal slide card releasing means is preferably in the form of a release button located in yet another of the plurality of side panels.
The present invention comprises various improvements to the sleeve element that contribute to the package stability. In one such modification, the sleeve blank may be cut to include an extension which, when folded inward, creates a false bottom in the lower end of the package. This false bottom, which is positioned beneath the release button located on the exterior of the paperboard sleeve, provides structural support to the package and causes the sleeve to be more resistant to deformation by squeezing or crushing. This feature is useful because such deformation can allow the release mechanism to be depressed and the locking mechanism of the package disengaged, thereby providing inadvertent access to the package contents. The inclusion of the false bottom also allows the release button to be located more towards the center of the package without also changing the dimensions of the internal slide card. This placement makes access to the release mechanism more difficult for a child.
Alternatively, areas of the sleeve that are susceptible to tearing may be formed from a double thickness of the substrate material. This feature reduces the possibility that the package may be torn open and also increases the overall sturdiness of the package exterior. To achieve this doubled thickness, the blank for forming the sleeve may be cut to include one or more panel extensions which can then be folded to lay parallel and adjacent to one or both side panels of the package. In one preferred embodiment, the panel extensions are formed at the side panels to provide a doubled thickness at the sleeve edges.
Depending on the choice of substrate material, another means of improving the impenetrability of the sleeve involves lamination of at least a part of one or both sides of the blank with a polymer film. In this manner, the exterior of the package is made more resistant to tearing. Optionally, this lamination may not extend over the entire surface of the sleeve blank. For example, only tear prone regions may require lamination. Suitable laminating materials may, for example, be selected from biaxially oriented or cross-laminated polymeric films such as high density polyethylene (HDPE), polyolefins, polyesters, e.g. Mylar(trademark), or combinations thereof. In a related embodiment, tear resistance may be provided at stress points such as the package corners and exposed edges by applying one or more strips of the polymeric film, e.g. as a tape, over these areas. In either aspect, the polymeric film may be applied by extrusion or adhesive lamination, or by any other suitable means known in the art, typically to the side that is the interior surface of the blank. It has been found that this treatment significantly increases tear resistance and prevents tear propagation in the outer sleeve. Preferably, neither the complete laminate film nor the selectively applied film strips will detract from the package""s aesthetic appearance or interfere with printability or any of the other desirable display features. Text or graphic information may be printed on the sleeve or on the surfaces of the internal slide card according to any means conventionally known in the art.
Another feature that suitably contributes to the child resistance of the package according to the invention is the positioning of the cut-aways or notches for withdrawing the slide card from the interior of the sleeve. The package disclosed in U.S. Pat. No. 6,047,829 included notches that were symmetrically placed on corresponding edges of the side panels to form a cut out. According to the present invention, the placement of the notches is altered such that each notch on one side panel is offset from the other, with only a small area of overlap forming a cut out area exposing the edge of the internal slide card. To open the package, the user must therefore grasp the slide card through the offset notches. Because this step requires asymmetric placement of the fingers, which is counter-instinctive to children, their ability to grasp and withdraw the slide card is greatly reduced.
In other preferred embodiments of the invention, the outer sleeve of the package provides additional protection for the internal slide card, which houses the unit dose product being used. The internal slide card has a stop feature, typically a folded extension thereof, that engages with a catch feature, typically also a folded extension, on the outer sleeve, to prevent the user from pulling the internal slide card completely away from the outer sleeve.
Optionally, other means for improving the structural integrity of the overall package may be incorporated. Such features include lamination of the slide card with a polymeric film, as described above, which also improves tear resistance.